We shall continue to study higher order structures in chromosomes with the high voltage electron microscope at the University of Wisconsin-Madison. Emphasis will be (1) on the structure of chromomeres in polytene chromosomes of diptera, (2) on the nature of chromosome condensation in somatic and meiotic prophase and in prematurely condensed chromosomes, (3) on the nature of chromatin-microtuble relationship in the kinetochore of mammals, insects, yeast and the diffuse kinetochore in Homoptera.